Be interesting if this was simply spedd thru the water, or VMG was better too as sailing further; but faster; or even sailing faster so apparent built so could bear off more anbd thus better VMG....

You will have to step me through that one Simon.. Are you saying that it is logical that flatter gives better VMG?

The next time I forget to let off the downhaul DURING the downwind leg I'm sure I'm going to remember that less draft/camber = more speed.
I've only just got into the habit of letting off the downhaul prior to the windward mark so as not to overstretch the luff whilst easing the main and traveller.
Oh well I might as well use one of John Pierce's famous quotes;
"The mainsail doesn't know you're going downwind!"

First off with the downhaul, _THEN_ grab the spi halyard

On the Tornado in the days before we got the spi we used to pull on some downhaul when conditions were extreme but we still wanted max speed downwind. It calmed down the boat a lot in my opinion.

I noticed Glenn Ashby saying that the downhaul should be let off before rounding the top mark on the A-cat some time ago. He should know even though I do think it is the luff rope and tape that carry the load from the downhaul, not the panels. I am not going to say against Glenn on the topic.

Hiya Mark, I was talking about the Solid sail. With Solid sails, you can create massive camber if you want to, but it is high drag.

I'm GUESSING Gashby sailed it more like an A class rig (so still fairly tight mainsheet, with about 12-18 inches of traveller eased) and then fly a hull downwind.

We have sails that we can only take from small amounts of camber to flat. A 3 part wing you can tune to give it much more camber and I assume this is what Gashy was doing different. Geep airflow over the sail going faster.

Mark, I totally agree, we have to let our downhaul off to sail down wind as we do not have very tunable sails compared with a Solid sail!

Hi all,

well all depends how full your sail can be. If the sail is to full, it will not create more lift, but less, because it is partly stalling. And less lift on a downwind leg is slower, as I said, you can forget about drag on downwind legs. So yes keep your sail flat, but not as flat as on a upwind leg. As mentioned before, tell tales on the leach will help to find the right point.

Finally I would not compare the settings of a solid wing with a soft sail. For most airfoil sections without slots more than 5%..7% camber will not improve lift capability, on a soft sail this might be the up-wind setting (including the mast in the camber calculation).

A bit off-topic: The performance of a wing sail against a modern squarehead sail has still to be proven. Last true competition was the rig selection for Stars and Stripes as far as I know, and soft sails has improved a lot since then.

Cheers,

Klaus

This is also a good idea because, in the event you pitch-pole going downwind, your fragile carbon A-cat mast won't be in full compression when it hits the water - reducing the chance of a failure.